The present invention relates to a method of and apparatus for aligning the components of an optical measuring system preparatory to using them in a measuring operation.
One known type of optical measuring system consists of two or more housings, at least one of which is to be fixed to the bed of the machine and another one of which is to be carried by the arm or spindle of the machine. Either one or both of the machine bed and machine spindle is movable. One of the housings contains one or more light sources and detectors, and will be referred to hereinafter as the “source housing” while the other housing contains reflectors, and will be referred to hereinafter as the “reflector housing”. Usually the source housing is maintained in a fixed position on the bed of the machine and the reflector housing is mounted on a part of the machine moveable with respect to the machine bed e.g. the machine spindle.
Aligning the optical components is often a time-consuming process which involves firstly the alignment of the source housing so that the beam or beams generated are directed along, or parallel to, one or more of the X, Y and Z axes of the machine. Then the reflectors have to be aligned with the beam or beams so that the reflected beams are directed back onto the detectors. Depending on the type of detectors being used the alignment may have to be accurate to within a few arc seconds.